Distributed power supply grid-connected intelligent power quality on-line monitoring device

Abstract

The utility model relates to the technical field of electric energy monitoring, in particular to a distributed power supply grid-connected intelligent electric energy quality on-line monitoring device, which comprises a main control module, a voltage sampling module, a current sampling module and two conditioning modules, the output ends of the voltage sampling module and the current sampling module are respectively connected with the input ends of the two conditioning modules, the main control module uses a single chip with a built-in analog-to-digital conversion function, and the output ends of the two conditioning modules are respectively connected with different input pins of the single chip microcomputer. According to the utility model, the voltage sampling module and the current sampling module respectively acquire voltage data and current data, then signals are amplified through the conditioning module, finally the main control module processes the data, the storage module stores the data, and the communication module sends the data, so that the equipment is simple and the practicability is stronger.

Description

Technical Field

[0001] The utility model relates to the technical field of electric energy monitoring, and specifically, to an online intelligent electric energy quality monitoring device for distributed power grid connection. Background Technique

[0002] Under the background of the global response to climate change and energy transformation, the proportion of distributed power sources such as solar photovoltaic power generation and wind power generation in the energy field is increasing day by day; distributed power sources have the advantages of being clean, renewable, flexible, etc., and can effectively supplement the deficiencies of traditional centralized power supply, providing strong support for the diversification and sustainable development of energy supply.

[0003] The access of distributed power sources brings a series of electric energy quality problems to the power grid. Since the output power of distributed power sources is random and volatile, such as solar energy being affected by weather and wind power being affected by wind speed changes, this leads to prominent problems such as voltage fluctuations, harmonic pollution, and three-phase imbalance in the power grid; these electric energy quality problems will not only affect the stable operation of the power grid, but may also damage the normal operation and service life of power equipment, reducing power supply reliability and electric energy quality.

[0004] Traditional electric energy quality monitoring devices have many deficiencies when dealing with the complex situations of distributed power grid connection, and there is a problem of complex device structure. Content of the Utility Model

[0005] The purpose of the utility model is to provide an online intelligent electric energy quality monitoring device for distributed power grid connection to solve the problems put forward in the above background technique.

[0006] To achieve the above purpose, the utility model provides the following technical solutions:

[0007] An online intelligent electric energy quality monitoring device for distributed power grid connection includes a main control module, and also includes a voltage sampling module, a current sampling module, and two conditioning modules. The output ends of the voltage sampling module and the current sampling module are respectively connected to the input ends of the two conditioning modules. The main control module uses a single chip with an internal analog-to-digital conversion function, and the output ends of the two conditioning modules are respectively connected to different input pins of the single chip.

[0008] Preferably, the conditioning module includes diode D1, diode D2, operational amplifier U1, resistor R2, resistor R3, capacitor C1, potentiometer RL1, capacitor C2, resistor R4, resistor R5, operational amplifier U2, resistor R6, capacitor C3, resistor R7, resistor R8, capacitor C4, operational amplifier U3, resistor R9, resistor R10, resistor R11, capacitor C5, and capacitor C6;

[0009] Both ends of the diode D1 serve as the input end of the conditioning module. The positive electrode of the diode D2 is connected to the negative electrode of the diode D1, and the negative electrode of the diode D2 is connected to the positive electrode of the diode D1. The positive electrode of the diode D2 is also connected to the non-inverting input end of the operational amplifier U1, and the negative electrode of the diode D2 is also connected to the inverting input end of the operational amplifier U1. The first end of the resistor R2 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R2 is connected to the first end of the potentiometer RL1, and the second end and the movable end of the potentiometer RL1 are connected to the output end of the operational amplifier U1. The first end of the resistor R3 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R3 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is connected to the output end of the operational amplifier U1. The first end of the capacitor C2 is connected to the output end of the operational amplifier U1, and the second end of the capacitor C2 is grounded. The first end of the resistor R4 is connected to the output end of the operational amplifier U1, and the resistor R4 is connected to the non-inverting input end of the operational amplifier U2. The first end of the resistor R5 is connected to the non-inverting input end of the operational amplifier U2, and the second end of the resistor R5 is grounded. The inverting input end of the operational amplifier U2 is connected to the output end of the operational amplifier U2. The first end of the resistor R6 is connected to the output end of the operational amplifier U2, the second end of the resistor R6 is connected to the first end of the resistor R7, and the second end of the resistor R7 is connected to the inverting input end of the operational amplifier U3. The first end of the capacitor C3 is connected to the second end of the resistor R6, and the second end of the capacitor C3 is grounded. The first end of the resistor R8 is connected to the second end of the resistor R6, and the second end of the resistor R8 is connected to the output end of the operational amplifier U3. The first end of the capacitor C4 is connected to the inverting input end of the operational amplifier U3, and the second end of the capacitor C4 is connected to the output end of the operational amplifier U3. The first end of the capacitor C5 is connected to the 5.0V power supply, and the second end of the capacitor C5 is grounded. The first end of the resistor R9 is connected to the first end of the capacitor C5, the second end of the resistor R9 is connected to the first end of the resistor R10, and the second end of the resistor R10 is grounded. The first end of the capacitor C6 is connected to the second end of the resistor R9, and the second end of the capacitor C6 is grounded. The first end of the resistor R11 is connected to the non-inverting input end of the operational amplifier U3, and the second end of the resistor R11 is connected to the first end of the capacitor C6. The output end of the operational amplifier U3 serves as the output end of the conditioning module.

[0010] Preferably, the voltage sampling module uses a voltage transformer. The two input ends of the voltage transformer are connected to the power supply to be measured through the resistor R1, and the two output ends of the voltage transformer serve as the output ends of the voltage sampling module.

[0011] Preferably, the current sampling module uses a current transformer. The current transformer is sleeved outside the wire connected to the power supply to be measured, and the two output ends of the current transformer serve as the output ends of the current sampling module.

[0012] Preferably, a communication module is further included, and the communication module is signal-connected to the main control module.

[0013] Preferably, a storage module is further included, and the storage module is signal-connected to the main control module.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] By setting a voltage sampling module and a current sampling module, the present utility model respectively obtains voltage and current data, then amplifies the signals through a conditioning module, and finally processes the data by a main control module, stores the data by a storage module, and sends the data by a communication module. The device is simple and has stronger practicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram of the overall structure of the utility model;

[0017] Figure 2 is a schematic diagram of the structure of the voltage sampling module in the utility model;

[0018] Figure 3 is a schematic diagram of the structure of the current sampling module in the utility model;

[0019] Figure 4 is a schematic diagram of the structure of the conditioning module in the utility model;

[0020] In the figure:

[0021] 1. Main control module;

[0022] 2. Voltage sampling module;

[0023] 3. Current sampling module;

[0024] 4. Conditioning module;

[0025] 5. Communication module;

[0026] 6. Storage module. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] Next, the technical solutions in the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0028] Please refer to Figures 1 - 4 , the present utility model provides the following technical solutions:

[0029] A distributed power grid-connected intelligent on-line power quality monitoring device includes a main control module 1, and also includes a voltage sampling module 2, a current sampling module 3, and two conditioning modules 4. The output ends of the voltage sampling module 2 and the current sampling module 3 are respectively connected to the input ends of the two conditioning modules 4. The main control module 1 uses a single chip with built-in analog-to-digital conversion function. The output ends of the two conditioning modules 4 are respectively connected to different input pins of the single chip to obtain voltage and current data, and data such as frequency and harmonic can also be obtained. The device is simple, can quickly obtain power quality data, and has stronger practicability.

[0030] In this embodiment, the two conditioning modules 4 change the amplification factor by changing the values of resistors and capacitors. Two conditioning modules 4 are required to be respectively matched with the voltage sampling module 2 and the current sampling module 3. The operational amplifier U1 and the peripheral circuit amplify the input signal to a range acceptable to the single-chip microcomputer pin. The operational amplifier U2 and the operational amplifier U3 form a low-pass filter to remove high-frequency clutter. The conditioning module 4 includes diodes D1, D2, operational amplifier U1, resistor R2, resistor R3, capacitor C1, potentiometer RL1, capacitor C2, resistor R4, resistor R5, operational amplifier U2, resistor R6, capacitor C3, resistor R7, resistor R8, capacitor C4, operational amplifier U3, resistor R9, resistor R10, resistor R11, capacitor C5 and capacitor C6;

[0031] Both ends of the diode D1 serve as the input end of the conditioning module 4. The positive electrode of the diode D2 is connected to the negative electrode of the diode D1, and the negative electrode of the diode D2 is connected to the positive electrode of the diode D1. The positive electrode of the diode D2 is also connected to the non-inverting input end of the operational amplifier U1, and the negative electrode of the diode D2 is also connected to the inverting input end of the operational amplifier U1. The first end of the resistor R2 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R2 is connected to the first end of the potentiometer RL1, and the second end and the movable end of the potentiometer RL1 are connected to the output end of the operational amplifier U1. The first end of the resistor R3 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R3 is connected to the first end of the capacitor C1, and the second end of the capacitor C1 is connected to the output end of the operational amplifier U1. The first end of the capacitor C2 is connected to the output end of the operational amplifier U1, and the second end of the capacitor C2 is grounded. The first end of the resistor R4 is connected to the output end of the operational amplifier U1, and the resistor R4 is connected to the non-inverting input end of the operational amplifier U2. The first end of the resistor R5 is connected to the non-inverting input end of the operational amplifier U2, and the second end of the resistor R5 is grounded. The inverting input end of the operational amplifier U2 is connected to the output end of the operational amplifier U2. The first end of the resistor R6 is connected to the output end of the operational amplifier U2, the second end of the resistor R6 is connected to the first end of the resistor R7, and the second end of the resistor R7 is connected to the inverting input end of the operational amplifier U3. The first end of the capacitor C3 is connected to the second end of the resistor R6, and the second end of the capacitor C3 is grounded. The first end of the resistor R8 is connected to the second end of the resistor R6, and the second end of the resistor R8 is connected to the output end of the operational amplifier U3. The first end of the capacitor C4 is connected to the inverting input end of the operational amplifier U3, and the second end of the capacitor C4 is connected to the output end of the operational amplifier U3. The first end of the capacitor C5 is connected to the 5.0V power supply, and the second end of the capacitor C5 is grounded. The first end of the resistor R9 is connected to the first end of the capacitor C5, the second end of the resistor R9 is connected to the first end of the resistor R10, and the second end of the resistor R10 is grounded. The first end of the capacitor C6 is connected to the second end of the resistor R9, and the second end of the capacitor C6 is grounded. The first end of the resistor R11 is connected to the non-inverting input end of the operational amplifier U3, and the second end of the resistor R11 is connected to the first end of the capacitor C6. The output end of the operational amplifier U3 serves as the output end of the conditioning module 4.

[0032] Specifically, the voltage sampling module 2 uses a voltage transformer. The two input ends of the voltage transformer are connected to the power supply to be measured through the resistor R1. The two output ends of the voltage transformer serve as the output ends of the voltage sampling module 2. The voltage transformer is based on the principle of electromagnetic induction and is similar to a transformer. The primary winding has more turns and is connected to a high voltage, while the secondary winding has fewer turns and outputs a lower voltage. By reasonably designing the turn ratio of the windings, the transformation of voltage is achieved.

[0033] Furthermore, the current sampling module 3 uses a current transformer. The current transformer is sleeved outside the wire connected to the power supply to be measured. The two output ends of the current transformer serve as the output ends of the current sampling module 3. The current transformer measures the current by inducing the magnetic field around the wire. When there is current passing through the wire, a magnetic field will be generated. The iron core of the current transformer will collect this magnetic field and induce a corresponding current in the secondary winding.

[0034] It should be noted that it further includes a communication module 5. The communication module 5 is signal-connected to the main control module 1. The communication module 5 can use a WIFI module or a 4G module to transmit the measured data to the server or the staff. The server can perform deeper data mining, and the staff can remotely monitor the power quality.

[0035] It is worth noting that it further includes a storage module 6. The storage module 6 is signal-connected to the main control module 1. The storage module 6 can use an SD card for storage and is connected through the SPI communication protocol.

[0036] When the distributed power grid-connected intelligent power quality on-line monitoring device of the present utility model is in use, the voltage sampling module 2 and the current sampling module 3 are respectively used to obtain voltage and current data. The operational amplifier U1 and the peripheral circuit in the conditioning module 4 form an amplification circuit, and the operational amplifier U2 and the operational amplifier U3 in the conditioning module 4 form a filtering circuit to amplify and filter the collected data. The main control module 1 processes the data through the built-in analog-to-digital conversion, can monitor the power quality after the distributed power grid connection in real time, obtain electrical parameters such as voltage, current, frequency, and harmonics, discover problems in time and take measures to avoid the expansion of faults. Then, the data is stored through the storage module 6 and transmitted through the communication module 5.

[0037] The above shows and describes the basic principles, main features and advantages of the present utility model. Those skilled in the art should understand that the present utility model is not limited by the above embodiments. The above embodiments and the descriptions in the specification are only the preferred examples of the present utility model and are not used to limit the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed. The scope of protection claimed by the present utility model is defined by the appended claims and their equivalents.

Claims

1. An intelligent on-line monitoring device for power quality of distributed power grid connection, comprising a main control module (1), characterized in that: It further includes a voltage sampling module (2), a current sampling module (3), and two conditioning modules (4). The output ends of the voltage sampling module (2) and the current sampling module (3) are respectively connected to the input ends of the two conditioning modules (4). The main control module (1) uses a single chip with built-in analog-to-digital conversion function. The output ends of the two conditioning modules (4) are respectively connected to different input pins of the single chip microcomputer.

2. The online intelligent power quality monitoring device for distributed power grid connection according to claim 1, characterized in that: The conditioning module (4) includes a diode D1, a diode D2, an operational amplifier U1, a resistor R2, a resistor R3, a capacitor C1, a potentiometer RL1, a capacitor C2, a resistor R4, a resistor R5, an operational amplifier U2, a resistor R6, a capacitor C3, a resistor R7, a resistor R8, a capacitor C4, an operational amplifier U3, a resistor R9, a resistor R10, a resistor R11, a capacitor C5, and a capacitor C6; Both ends of the diode D1 serve as the input end of the conditioning module (4). The positive electrode of the diode D2 is connected to the negative electrode of the diode D1, and the negative electrode of the diode D2 is connected to the positive electrode of the diode D1. The positive electrode of the diode D2 is also connected to the non-inverting input end of the operational amplifier U1, and the negative electrode of the diode D2 is also connected to the inverting input end of the operational amplifier U1. The first end of the resistor R2 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R2 is connected to the first end of the potentiometer RL1, the second end and the movable end of the potentiometer RL1 are connected to the output end of the operational amplifier U1. The first end of the resistor R3 is connected to the inverting input end of the operational amplifier U1, the second end of the resistor R3 is connected to the first end of the capacitor C1, the second end of the capacitor C1 is connected to the output end of the operational amplifier U1. The first end of the capacitor C2 is connected to the output end of the operational amplifier U1, the second end of the capacitor C2 is grounded. The first end of the resistor R4 is connected to the output end of the operational amplifier U1, the resistor R4 is connected to the non-inverting input end of the operational amplifier U2. The first end of the resistor R5 is connected to the non-inverting input end of the operational amplifier U2, the second end of the resistor R5 is grounded. The inverting input end of the operational amplifier U2 is connected to the output end of the operational amplifier U2. The first end of the resistor R6 is connected to the output end of the operational amplifier U2, the second end of the resistor R6 is connected to the first end of the resistor R7, the second end of the resistor R7 is connected to the inverting input end of the operational amplifier U3. The first end of the capacitor C3 is connected to the second end of the resistor R6, the second end of the capacitor C3 is grounded. The first end of the resistor R8 is connected to the second end of the resistor R6, the second end of the resistor R8 is connected to the output end of the operational amplifier U3. The first end of the capacitor C4 is connected to the inverting input end of the operational amplifier U3, the second end of the capacitor C4 is connected to the output end of the operational amplifier U3. The first end of the capacitor C5 is connected to the 5.0V power supply, the second end of the capacitor C5 is grounded. The first end of the resistor R9 is connected to the first end of the capacitor C5, the second end of the resistor R9 is connected to the first end of the resistor R10, the second end of the resistor R10 is grounded. The first end of the capacitor C6 is connected to the second end of the resistor R9, the second end of the capacitor C6 is grounded. The first end of the resistor R11 is connected to the non-inverting input end of the operational amplifier U3, the second end of the resistor R11 is connected to the first end of the capacitor C6. The output end of the operational amplifier U3 serves as the output end of the conditioning module (4).

3. The online intelligent power quality monitoring device for distributed power grid connection according to claim 1, characterized in that: The voltage sampling module (2) uses a voltage transformer. Two input terminals of the voltage transformer are connected to the power supply to be measured through a resistor R1, and two output terminals of the voltage transformer serve as the output terminals of the voltage sampling module (2).

4. The intelligent on-line power quality monitoring device for distributed power grid connection according to claim 1, characterized in that: The current sampling module (3) uses a current transformer. The current transformer is sleeved outside the wire connected to the power supply to be measured, and two output terminals of the current transformer serve as the output terminals of the current sampling module (3).

5. The on-line intelligent power quality monitoring device for grid-connected distributed power sources according to claim 1, characterized in that: It further includes a communication module (5), and the communication module (5) is signal-connected to the main control module (1).

6. The on-line intelligent power quality monitoring device for distributed power grid connection according to claim 1, characterized in that: It further includes a storage module (6), and the storage module (6) is signal-connected to the main control module (1).

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